CSS smooth bounce animation

Question

I needed to implement infinite bounce effect using pure CSS, so I referred this site and ended up doing this.

Answer 1

The long rest in between is due to your keyframe settings. Your current keyframe rules mean that the actual bounce happens only between 40% - 60% of the animation duration (that is, between 1s - 1.5s mark of the animation). Remove those rules and maybe even reduce the animation-duration to suit your needs.

.animated {
  -webkit-animation-duration: .5s;
  animation-duration: .5s;
  -webkit-animation-fill-mode: both;
  animation-fill-mode: both;
  -webkit-animation-timing-function: linear;
  animation-timing-function: linear;
  animation-iteration-count: infinite;
  -webkit-animation-iteration-count: infinite;
}
@-webkit-keyframes bounce {
  0%, 100% {
    -webkit-transform: translateY(0);
  }
  50% {
    -webkit-transform: translateY(-5px);
  }
}
@keyframes bounce {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-5px);
  }
}
.bounce {
  -webkit-animation-name: bounce;
  animation-name: bounce;
}
#animated-example {
  width: 20px;
  height: 20px;
  background-color: red;
  position: relative;
  top: 100px;
  left: 100px;
  border-radius: 50%;
}
hr {
  position: relative;
  top: 92px;
  left: -300px;
  width: 200px;
}

---

Here is how your original keyframe settings would be interpreted by the browser:

• At 0% (that is, at 0s or start of animation) - translate by 0px in Y axis.
• At 20% (that is, at 0.5s of animation) - translate by 0px in Y axis.
• At 40% (that is, at 1s of animation) - translate by 0px in Y axis.
• At 50% (that is, at 1.25s of animation) - translate by 5px in Y axis. This results in a gradual upward movement.
• At 60% (that is, at 1.5s of animation) - translate by 0px in Y axis. This results in a gradual downward movement.
• At 80% (that is, at 2s of animation) - translate by 0px in Y axis.
• At 100% (that is, at 2.5s or end of animation) - translate by 0px in Y axis.